842551 has 2 divisors, whose sum is σ = 842552. Its totient is φ = 842550.

The previous prime is 842531. The next prime is 842581. The reversal of 842551 is 155248.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 842551 - 2⁵ = 842519 is a prime.

It is a plaindrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (842521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 421275 + 421276.

It is an arithmetic number, because the mean of its divisors is an integer number (421276).

2⁸⁴²⁵⁵¹ is an apocalyptic number.

842551 is the 411-st centered decagonal number.

842551 is a deficient number, since it is larger than the sum of its proper divisors (1).

842551 is an equidigital number, since it uses as much as digits as its factorization.

842551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1600, while the sum is 25.

The square root of 842551 is about 917.9057685841. The cubic root of 842551 is about 94.4492976617.

Adding to 842551 its reverse (155248), we get a palindrome (997799).

The spelling of 842551 in words is "eight hundred forty-two thousand, five hundred fifty-one".